fix(planning): keep plans lightweight while preserving first-delivery quality

docs/reference/protocols/loopx-goal-command-v0.md

@@ -154,6 +154,19 @@ but the shape depends on how clear the goal already is:
   concise todos to make the approach explicit, without arbitrary item-count
   caps or management-only filler.
 
+The shared `budget_policy` now explicitly asks for the minimum plan needed to
+begin useful work: reuse covered Todos, identify the next executable step and its
+decisive validation, and defer uncertain later work to replan. Diagnostic validation,
+including permitted feedback, can be that first step before dependent implementation
+to strengthen the first deliverable. The quality objective and diagnostic means
+coexist: a diagnostic result does not replace the requested deliverable. Do not
+require exhaustive upfront decomposition. This changes default
+planning guidance for both `/loopx` and `todo plan`, in ordinary and fine-grained
+mode; it adds no fixed step/time limit or permission to skip planning/readback,
+task acceptance, quota admission or genuine blockers. The existing fine-grained
+one-checkpoint rule and broad-goal lane suggestions still apply. Lightweight
+planning does not mean early task completion or weaker delivery requirements.
+
 The shared planner now includes `first_delivery_guidance`, also rendered in the
 guided `/loopx` start prompt and the existing `todo plan` packet. This changes
 default Agent guidance in both ordinary and fine-grained planning: preserve a

loopx/control_plane/goals/start_contract.py

@@ -50,7 +50,11 @@ def goal_planner_contract(*, fine_grained: bool = False) -> dict[str, Any]:
         "default_task_class": "advancement_task",
         "required_fields": ["priority", "text", "task_class", "action_kind"],
         "public_safe_only": True,
-        "budget_policy": "minimum sufficient plan; no fixed-count filler",
+        "budget_policy": (
+            "minimum sufficient plan: next step and decisive validation; no fixed-count "
+            "filler or exhaustive decomposition. Diagnostics and feedback may come first "
+            "to strengthen delivery; replan uncertain later work."
+        ),
         "first_delivery_guidance": _FIRST_DELIVERY_GUIDANCE,
     }
     if fine_grained:

tests/control_plane/test_task_planning.py

@@ -92,6 +92,33 @@ def test_existing_plan_is_an_incremental_frontier_not_a_new_goal(bound_goal):
     assert all(item["todo_id"] != "todo_peer" for item in packet["existing_todos"])
 
 
+@pytest.mark.parametrize("fine_grained", [False, True])
+def test_planning_scope_is_sufficient_to_start_without_exhaustive_decomposition(bound_goal, fine_grained):
+    registry = bound_goal["registry_path"]
+    contents = json.loads(registry.read_text())
+    if fine_grained:
+        contents["goals"][0]["execution_profile"] = {"turn_granularity": "fine"}
+        registry.write_text(json.dumps(contents))
+    packet = build_task_planning_packet(**bound_goal)
+    planner = packet["planner"]
+    assert planner == goal_planner_contract(fine_grained=fine_grained)
+    for clause in (
+        "minimum sufficient plan: next step and decisive validation",
+        "Diagnostics and feedback may come first to strengthen delivery",
+        "replan uncertain later work",
+        "no fixed-count filler or exhaustive decomposition",
+    ):
+        assert clause in planner["budget_policy"]
+    assert planner["profiles"]["clear_bounded_problem"][
+        "may_reuse_current_todo_when_it_already_represents_the_plan"] is True
+    assert planner["required_before_todo_write"] is True
+    assert packet["execution_handoff"]["requires_quota_guard"] is True
+    assert packet["execution_handoff"]["planning_is_advancement"] is False
+    assert "do not substitute them for the requested deliverable" in planner["first_delivery_guidance"]
+    assert "existing acceptance, feedback and authority limits" in planner["first_delivery_guidance"]
+    assert planner.get("maximum_runnable_todos_written_ahead") == (1 if fine_grained else None)
+
+
 def test_unknown_identity_rejected_without_creating_it(bound_goal):
     with pytest.raises(ValueError, match="not registered"):
         build_task_planning_packet(**(bound_goal | {"agent_id": "unknown"}))